Generally, common black developers have been heretofore used widely in image-forming apparatuses such as electrophotographic copying machines and laser printers. In recent years, however, compact sized image-forming apparatuses for personal use have been popularized and the users' application has been widened, so that not only black-color images but also the other color images and multicolor-images superimposed with different colors thereon have been very often used.
Because the developers are consumed by making use of the above-mentioned image-forming apparatus, the developers are to be replenished. The replenishments are generally carried out in the following manner. A developer container containing a developer is inserted into a developer replenisher of the main body of the apparatus and the cover for the developer replenisher and the cover for the developer container are opened and closed in the inserted state, so that the developer inside the developer container may be replenished from the developer replenisher.
In such an image-forming apparatus as mentioned above, however, when trying to replenish a certain color developer from a developer container containing the same color developer into a developing section and if erroneously replenishing some different color developer from a developer container containing the different color developer, there may be a possibility of making the apparatus unusable at all until the developing section is overhauled to be cleaned up.
Therefore, as disclosed each in Japanese Patent Publication Open to Public Inspection (hereinafter abbreviated to JP OPI Publication) Nos. 3-267965/1991 and 3-269461/1991, there are some apparatuses in which it is made impossible to insert any developer container containing different color developer into a developer replenisher of the main apparatus body, except that only a specific developer container can be inserted therein, so that the replenishments can be made only from a developer container containing the same color developer.
Even in an apparatus in which a specific developer container only can be inserted into the developer replenisher of the main apparatus body and if even a portion of the developer container containing a different color developer is inserted askew into the developer replenisher of the main apparatus body, there may be some instances where the cover for the developer replenisher may be opened by coupling it to the developer container of the main apparatus body, in the above-mentioned state. Therefore, a different kind of developer may sometimes be erroneously replenished from a developer replenisher of the main apparatus body or a trouble may be produced to make the developer adhere to the surroundings of the developer replenisher of the main apparatus body.
When a replenishment is carried out by an average user, he cannot discriminate whether the method of inserting a developer container is wrong or not and whether a wrong developer container is inserted or not. Therefore, not only does it takes a long time to replenish a developer, but also there is a possibility of damaging the developer container because he tries to forcibly insert the developer container containing a different kind of developer.
This invention has been achieved by taking the actual state of things into consideration. It is therefore an object of the invention to provide a simple-structured and easy-handling image-forming apparatus capable of preventing any replenishments of different color developers safely without damaging any developer container.